In contemporary communication systems communication connections, in particular real time connections, e.g. for voice, video or multimedia communication, are also increasingly routed via packet-oriented communication networks, e.g. local area networks or wide area networks. Internet telephony, also frequently referred to as VoIP telephony (Voice/Video over Internet Protocol) is for example based on this technology.
Modern packet-oriented real time communication systems are frequently based on a system architecture according to the ITU-T recommendation H.323. A so-called gatekeeper is generally provided for signaling control in such communication networks. While connection signaling is routed between connection end points via the gatekeeper, the user data to be transferred in the context of the connection is transmitted directly via user data channels set up between the connection end points. Communication systems according to the H.323 recommendation provide a wide range of service features known from conventional line-switched communication technology, such as call forwarding, call diversion and call waiting. A so-called pause and rerouting procedure is frequently implemented in H.323 communication networks to support or provide such service features. With the pause and rerouting procedure the gatekeeper prompts a respective connection end point to stop sending user data temporarily and to close the relevant user data channels. Once the user data channels are successfully closed, the gatekeeper can prompt the opening of new user data channels with modified characteristics or between other connection end points. Simple connection control can thus be implemented. The pause and rerouting procedure is for example described in section 8.4.6 of the H.323 recommendation.
In order to determine before new user data channels are opened whether the data channels to be closed have been closed successfully, according to the prior art to date all the user data channels of all existing connections have to be managed centrally by the gatekeeper. This also relates in particular to connections in which a pause and rerouting procedure is not executed. Such channel management however on the one hand requires a significant implementation outlay, both with regard to processing power and storage capacity, and on the other hand results in a greater susceptibility to error due to the database organization additionally required with its associated synchronization requirements. Both aspects have a negative impact on the scalability of a communication system.